wireless: carl9170: fix clang build warning

clang fails to eliminate some dead code with always-taken branches
when CONFIG_PROFILE_ANNOTATED_BRANCHES is set, leading to a false-positive
warning:

drivers/net/wireless/ath/carl9170/mac.c:522:3: error: variable 'power' is used uninitialized whenever 'if' condition is
      false [-Werror,-Wsometimes-uninitialized]
                BUG_ON(1);
                ^~~~~~~~~

Change both instances of BUG_ON(1) in carl9170 to the simpler BUG()
to avoid the warning.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NChristian Lamparter <chunkeey@gmail.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/carl9170/mac.c

@@ -519,7 +519,7 @@ int carl9170_set_mac_tpc(struct ar9170 *ar, struct ieee80211_channel *channel)
 		power = ar->power_5G_leg[0] & 0x3f;
 		break;
 	default:
-		BUG_ON(1);
+		BUG();
 	}
 
 	power = min_t(unsigned int, power, ar->hw->conf.power_level * 2);

drivers/net/wireless/ath/carl9170/rx.c

@@ -795,7 +795,7 @@ static void carl9170_rx_untie_data(struct ar9170 *ar, u8 *buf, int len)
 		break;
 
 	default:
-		BUG_ON(1);
+		BUG();
 		break;
 	}